1. Field of the Invention
The present disclosure relates to wireless communication systems, and more particularly to production testing of wireless communication systems.
2. Related Art
As the number and uses of wireless data communication systems increase, it has become increasingly important to the manufacturers of such systems to perform production testing of the wireless transceivers embedded in such systems in a more time-efficient manner. As is well known, a problem with production testing of such embedded transceivers is that no direct, e.g., wired, digital control connection is generally available between the device under test (DUT) and the test controller (e.g., personal computer). Instead, communication must take place through the host processor also embedded within the system. Accordingly, production testing becomes more complicated since testing firmware must be installed or stored for running on the embedded host processor.
While using firmware in an embedded processor may be acceptable for a single platform, this approach quickly becomes unacceptable when multiple platforms are involved and must be supported. Further, as is often the case, the wireless transceiver function, e.g., a wireless transceiver operating according to the IEEE 802.11 standard, is merely a small portion of the overall set of functions of the host system. Accordingly, the manufacturer, while interested in producing a fully functional wireless transceiver capability, is nonetheless not interested in spending significant resources on integrating the wireless function in view of its limited role in the overall operation of the system.
Many well-known and popular data communications systems include wireless transceivers that communicate via digital data signals in which the data is distributed among a number of data packets which are transmitted sequentially and then reassembled within the receiver, often following transmission along various distinct signal paths (e.g., as is done with the Internet). Conventional test equipment for measuring these data signals capture these data packets, store them and then transfer them for analysis. Often, the transfer and analysis of the captured data takes longer than the process by which they are captured from within the data signal, in part because of the need to transfer the captured data to remote analysis circuitry (e.g., a computer separate from the test equipment). Consecutive data packets are often closely spaced, particularly within data signals being transmitted at high data rates. Accordingly, conventional test equipment will often not measure consecutive packets, but instead will capture non-adjacent packets spaced in time by an interval approximating the time needed for analysis or measurement.
However, it is often desirable to capture consecutive packets, e.g., to analyze power variations from one packet to another. To do this with conventional test equipment, it would generally be necessary to increase the time interval available for capturing the data packets, thereby causing the capture window to become equal to the duration of the number of consecutive data packets sought to be captured and analyzed. This, however, is disadvantageous due to the fact that increasing the capture window will also slow down the overall data capture and analysis operation, since more data will need to be transferred between the capture memory and analysis engine. Further, in many communication systems, the data packets are not closely spaced, which means that much of the captured data is unused since it corresponds to the gaps between consecutive data packets.